1. Field of the Invention
The present invention relates to a support platform of a non-contact transfer apparatus, and more particularly, to a support platform that can transfer objects under a non-contact state.
2. Description of the Related Art
Generally, in order to manufacture a semiconductor integrated circuit or a display panel, an object (for example, a substrate) undergoes a plurality of processes.
In order to transfer the object from one process to another process, a transfer apparatus is used. A transfer apparatus that can efficiently transfer the object has been researched.
Transfer apparatuses are classified into contact transfer apparatuses that can transfer the object in a state where the object directly contacts a support platform and non-contact transfer apparatuses that can transfer the object in a state where the object is lifted by air pressure.
In the case of the contact transfer apparatus, since the object is transferred in a state where it contacts the support platform, the object may be scratched due to the friction between the object and the support platform or broken. In the case of the non-contact transfer apparatus, because the object is transferred without contacting the support platform, damage to the object can be minimized or prevented and pollution of the object by foreign objects can be lowered. Furthermore, there is no electrostatic problem caused by contact between the object and the support platform.
Recently, the non-contact transfer apparatus has been more actively studied.
FIG. 1 shows a support platform of a non-contact transfer apparatus according to the related art of the present invention.
Referring to FIG. 1, a related art support platform 100 of a non-contact transfer apparatus includes a plurality of unit cells each having a chess-table format. The unit cells are provided with a plurality of air intake hole portions 101 and a plurality of air exhaust holes 102. The air is sprayed toward an object 106 through the air intake hole portions 101 and is then exhausted to an external side through the air exhaust holes 102. Air is sprayed toward an object 106 through the air intake hole portions 101 and is then exhausted to an external side through the air exhaust holes 102.
When the object 106 that may have a size equal to, greater or less than that of an active surface 107 of the platform 100 is arranged close to the active surface 107 in parallel, an air cushion 104 is formed between a bottom surface of the object 106 and the active surface 107. The air cushion 104 provides a pressure for uniformly lifting the object 106. The intensity of the pressure depends on an amount of air introduced through the air intake hole portions 101 and an amount of air exhausted through the air exhaust holes 102.
The object 106 may be transferred in the arrow direction in FIG. 1.
The air intake hole portions 101 are connected to a pressure storing unit 108 connected to an air pump 109. Therefore, the air taken in the air pump 109 is stored in the pressure storing unit 108 and is then relaxed through the air intake hole portions 101. The released air forms the air cushion 104 to transfer the object in a state where the object 106 is lifted from the active surface 107 of the platform 100 by a predetermined interval.
In the non-contact transfer apparatus of the related art, since each air intake hole 101 through which the air is introduced has a predetermined diameter, a large amount of air is consumed to form the air cushion 104 on the active surface 107, thereby increasing the process costs.
In addition, since not only the pitches between the holes 101 and 102 but also the diameters of the holes 101 and 102 are identical to each other, the pressure at a central portion of the support platform is greater than that at the peripheral portion of the support platform. That is, the pressure distribution is not uniform throughout the active surface of the support platform. Therefore, the object lifted from the platform may jolt or collide with a periphery of the object. This causes damage to the object.